Fabrication and characterization of novel porous hydrogels for fragile fruits: A case study

Abstract

Mechanical damage during transportation impairs fruit quality. Protecting fragile fruits through packaging is essential. Herein, this paper presents a case study of fresh strawberries embeded in porous hydrogels (PHs) to maintain quality and avoid damage during shelf-life period. The hydrogels were biologically fabricated using alginate networks and soy protein isolates to yield a porous structure. With three times of foaming rate, the PH could dissipate 70%–78% deformation energy in the first loading cycles. It also maintained an energy dissipation rate of 51.52% after 200 loading cycles. The strawberries stored in these PHs exhibited a remarkably better quality than those in other package materials after transportation simulation and free-fall tests, their damage indices were inhibited under 14% (above 36% in control). Additionally, during a two-day shelf-life period, rotten rate of strawberries after transportation simulation and that after free-fall tests were detected as 2.49 ± 1.86% (48.33 ± 5.67% in control) and 13.34 ± 3.76% (94.96 ± 3.76% in control), respectively. Moreover, PHs possessed a high specific heat capacity of 3956 ± 49 J kg −1 K −1 and a low friction coefficient of 0.081 ± 0.003, maintaining a low temperature around the fruit and avoiding fruit abrasion. The PHs were also biodegradable. Therefore, the PHs was considered as promising packaging for maintaining fresh and fragile produce. • A porous hydrogel-based package material was designed to transport fragile fruit. • The porous hydrogel is edible, economical, biodegradable, easily operable. • The porous hydrogels dissipated 70%–78% deformation energy. • Fruits protected by the porous hydrogel exhibited better quality than other packaging. • The porous hydrogel possessed a high specific heat capacity of 3956 ± 49 J kg −1 K −1 .